Most investors have heard the advice so often it sounds like common sense: start with a small position, see if you’re right, and add once the trade proves itself. It feels careful. For the way we manage money, it gets the order wrong.
We don’t decide how much to own based on how strongly we feel about an idea. We decide how much of the portfolio we’re willing to lose if we’re wrong, define where we’ll exit, and let those two decisions determine the position size. When an opportunity meets our standards and fits within the portfolio’s risk limits, we take the full risk-budgeted position from the beginning.
That doesn’t mean the largest position we could take. It means the position our risk process says we should take.
Position size is the output.
Dollars Invested Aren’t Dollars at Risk
Consider a $10 million portfolio. Suppose we decide that one position can put no more than 1% of the portfolio at planned risk, or $100,000.
For a stock or ETF position, the arithmetic is straightforward. If the exit is 5% below the entry price, the position can be $2 million. If the exit is 10% away, the position can be $1 million. If the exit is 20% away, the position can be $500,000. In each case, the planned risk is the same: $100,000.
A $2 million position with a 5% exit can carry the same planned risk as a $500,000 position with a 20% exit. A large position isn’t necessarily a large risk, and a small position isn’t necessarily a small one.
The amount invested tells us how much capital is exposed. The risk budget tells us how much we’re willing to lose. The exit defines the distance between the entry and the point where we’re no longer willing to own the position. Together, those decisions determine the size.
For nonlinear exposures such as options, the calculation is different: it starts from the payoff structure and the scenario loss. The principle is the same. Define the downside first, then determine the exposure.
What a Starter Position Really Changes
There are legitimate reasons to scale into a position. A strategy may have been designed and tested around adding exposure in stages. Liquidity may require it. Important information may arrive over time. That isn’t what we’re talking about.
We mean an opportunity that has already met our entry criteria, has a defined exit, fits within the portfolio, and has earned a particular risk budget, and then gets bought at a fraction of its calculated size simply because starting small feels safer.
Taking half the calculated position certainly reduces the dollars initially at risk. But it also changes the payoff. If the position starts working immediately, we participate in that move with less exposure than our own risk process determined we could carry. By the time it has “proven itself,” the price may be higher, the original entry is gone, the distance to the exit may have changed, and the expected payoff may be less attractive. We may end up putting more capital at risk after the opportunity has become worse.
That isn’t necessarily safer. It’s a different bet.
Taking the full risk-budgeted position doesn’t necessarily mean executing the entire order at once. Liquidity, spreads, and market impact can affect how we work the order. The intended exposure is determined first; execution is a separate decision.
Comfort isn’t a sizing rule.
A Full Position Isn’t a Statement of Confidence
A full risk-budgeted position isn’t a declaration that we’re certain. We’re never certain. It’s the amount of exposure justified by a predefined amount of risk.
Confidence is subjective. It changes with recent price action, headlines, narratives, and emotion. Risk architecture shouldn’t.
The evidence determines whether a position belongs in the portfolio. The risk budget determines how much we’re willing to lose. The exit defines the distance. Those decisions determine the size, and that keeps position sizing tied to the portfolio rather than to how persuasive an idea happens to feel.
The Portfolio Is the Unit of Risk
A properly sized position can still be wrong, and several properly sized positions can be wrong at the same time. That’s why the portfolio matters more than any individual position.
Every open position carries planned risk, and those risks accumulate. Ten individually reasonable positions can still create an unreasonable portfolio if they’re all vulnerable to the same underlying force. What looks diversified by ticker symbol may still be concentrated by risk: several different securities can respond to the same interest-rate shock, liquidity event, or change in investor behavior. Two positions driven by the same underlying risk can be closer to one bet than two.
So we care about more than the number of positions we own. We care about concentration, correlation, liquidity, common risk drivers, and the portfolio’s total open risk.
An exit defines planned risk, not the maximum possible loss. Markets can gap through an exit. Liquidity can disappear. Several positions can move against us at once. That’s why we don’t treat an exit as a guarantee, and why we manage risk across the whole portfolio rather than assuming every exit will execute exactly where we planned it.
The portfolio comes first. Individual positions are subordinate to it.
Why I Do It This Way
No investment process can make every position profitable, and ours isn’t designed around that objective. The objective is to make being wrong manageable while allowing being right to matter. A controlled loss is part of managing money. A loss large enough to permanently impair the capital base is something else entirely, because losses compound against you: the more capital that disappears, the larger the return required just to get back to even.
I’ve managed positions this way for more than twenty years. Once an opportunity qualifies, fits the portfolio, has a defined exit, and earns a risk budget, I don’t need to buy a token amount to see how I feel about it. The position has either earned the risk or it hasn’t. If it hasn’t, we don’t take it. If it has, we size it properly from the beginning.
New evidence can change that decision tomorrow. We can reduce the position, exit it, rotate somewhere else, or determine that the original thesis no longer holds. But those are responses to new information. Starting undersized because the calculated position feels uncomfortable is something different.
That’s how we approach positions in ASYMMETRY® Managed Portfolios. For a family whose wealth may represent decades of work, the sale of a business, or capital intended to support future generations, the first question shouldn’t be how much a position might make. It should be:
How much are we willing to lose if we’re wrong?
The evidence determines whether we take the risk. The risk budget determines how much we’re willing to lose. The exit defines the distance. The portfolio determines whether the risk fits. And those decisions determine the size.
Position size is the output.
Mike Shell is the founder and chief investment officer of Shell Capital Management, LLC, a registered investment adviser. He serves as portfolio manager of ASYMMETRY® Managed Portfolios, a separately managed account program with trade execution and custody provided by Goldman Sachs Custody Solutions.
ASYMMETRY® Observations are provided for general informational and educational purposes only. They do not constitute investment advice, a recommendation, or an offer to buy or sell any security or investment strategy. The content is not intended to be a complete description of Shell Capital’s investment process and should not be relied upon as the sole basis for any investment decision.
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